A federal judge opened the way for the former SNTE president's prosecution for tax fraud last Tuesday, the AG's office said.

The allegation "is based on evidence that shows that Gordillo Morales declared income on her 2008 income tax return that was substantially less than the actual amount," the AG's office said in a statement.

Gordillo, who ran the SNTE for more than two decades, was arrested on Feb. 26 on a warrant issued by a judge at the request of the federal AG's office.

Prosecutors allege that Gordillo, who was considered the most powerful woman in Mexico, used union funds to pay personal expenses.

Gordillo, once described by scholar M. Delal Baer as "Jimmy Hoffa in a dress," used union funds to pay credit card bills, make purchases at luxury stores, have cosmetic surgery, purchase real estate and cover other spending, prosecutors allege.

The former union boss was expelled from the governing Institutional Revolutionary Party, or PRI, in 2006 for helping create the New Alliance Party, or PANAL, which tried unsuccessfully to form a coalition with Enrique Peña Nieto, who won last year's presidential election.